While the overlay is still open -- this is the important bit -- scroll down to the editor.

Close the overlay any way you like.

Click on your avatar in the quick reply area.

Open the trophy points overlay.

The above screenshots should resemble what happens.

I think the important factors are that it is an overlay which has previously been opened, cached and closed, and you're scrolling down the page so when the cached overlay opens, it's opening above an element that wasn't on the screen previously.

This is pretty edge case stuff, I guess, but as you can see if it does happen, it's not pretty.

When the overlay loads again, the z-index remains at auto. Presumably because it's cached and it effectively just unhides itself. The function that unhides a cached overlay should set the z-index back to 9999.

While the overlay is still open -- this is the important bit -- scroll down to the editor.

Close the overlay any way you like.

Click on your avatar in the quick reply area.

Open the trophy points overlay.

The above screenshots should resemble what happens.

I think the important factors are that it is an overlay which has previously been opened, cached and closed, and you're scrolling down the page so when the cached overlay opens, it's opening above an element that wasn't on the screen previously.

This is pretty edge case stuff, I guess, but as you can see if it does happen, it's not pretty.

When the overlay loads again, the z-index remains at auto. Presumably because it's cached and it effectively just unhides itself. The function that unhides a cached overlay should set the z-index back to 9999.